The Design Of The Boost Switch Mode Power IC Based On Peak Current PWM Control

The content of this thesis is to design a BOOST DC to DC Power switch supply management chip. It has very high conversion efficiency, high integration, lowest component count switcher solution and wide range input voltage. Actually, the trend of switch supply management IC design is towards high integration, and high efficiency and so on. In order to satisfy the requirement of specifications above, the paper designs the main circuit and control system of the chip separately and makes every functional module parameter. At last the paper achieves circuits of every functional module and the whole chip.The paper analyzes all-sided BOOT converter, including DCM and CCM. Modeling of peak current control BOOT converters and transfer function are established, so system stability and response rate are designed better.This thesis analyzes the circuit and system's characteristic of the peak current control PWM BOOST carefully, and then a novel circuit structure is presented in this thesis, which is used to a current-mode, fixed-frequency, pulse-width modulation architecture for fast transient response and low-noise operation. The high switching frequency (1.2MHz) allows the use of low profile inductors and ceramic capacitors to minimize the thickness of LCD panel designs.The integrated high-efficiency MOSFET and the IC's built-in digital soft-start function reduce the number of external components required. The output voltage can be set from input voltage to 13V with an external resistive voltage-divider. Use of pulse skipping mode operation improve efficiency and further reduce power consumption. The typical circuit operates from an input voltage as low as 1.8V, and produces a main output of 10V at 250mA.Based on this thesis, a peak current control PWM BOOST converter is designed, which is fabricated with 0.8μm CMOS process and integrated with high precision voltage reference, Oscillator, Slope-compensation function circuit, current sensing circuit, Error amplifier, Digital soft-start, PWM logic and so on. The BOOST converter can work in different operations for choosing different external components to meet the demand of Switch mode power supply application. Besides, it also has some excellent characteristics, such as lower output ripple, high convert efficiency, well transient response performance and strong ability of load regulation. In the condition of typical application, output voltage ripple is less than±1%, convert efficiency is up to 85%, when the load current step from 100mA to 300mA, the dynamic sag is only 0.5% and the restore time is 125μs.